I think that most girls are uncomfortable when they start wearing bras. I know I was and I couldn't wait to start wearing them. Then I got them and changed my mind. You say that you have bought some for her. Have you taken her out so that she could pick them. I know nothing is as embarassing as bra shopping with your mom. Does she have an older sister, older friend or cousin that could also go. That way you would still be there, but you wouldn't have to be near the dressing room or bra department when she was looking at them, but she would still have someone to help her and give opinions. Just a thought.

Also, I don't know how overweight she is, but maybe she needs to look at bras in a specialty store. Like Lane Bryant. I'm sure that if she's a bit bigger all of the teenybopper bras aren't the right fit for her.